Atomistic study on the effects of hydride precipitation on the shock behavior of single crystal zirconium

The present study employed non-equilibrium molecular dynamics simulations to investigate the effects of hydride precipitation on the shock response of single-crystal zirconium (Zr). The anisotropic behavior of Zr was explored by subjecting the shock loading along various crystallographic directions. To assess the influence of hydride precipitation, the simulations were conducted for hydride precipitates oriented parallel and perpendicular to the shock front, considering different hydride phases and various precipitate sizes. Shock response was characterized by spectra-temporal distribution of particle velocity, pressure, and density, along with the evaluation of shock front velocity and spall damage. The results indicate that shock loading along the [0001] and [11 2 ‾ 0] orientations lead to a higher degree of phase transformation compared to the [ 1 ‾ 100] orientation, which resulted in a reduction in shock velocity. In configurations with hydride precipitate, the presence of hydride facilitated the initiation of void nucleation at the Zr-hydride interface. As the piston velocity increases, this void formation eventually leads to the spallation. At a particle velocity of 1.25 km/s, the spall strength of the hydride precipitate configuration was evaluated to be 13.34 GPa, while no spallation was observed in the pristine Zr configuration. Spall strength decreases with increasing hydride size and hydrogen concentration in hydride phase due to intensified interfacial effects. This highlights the adverse impact of hydride precipitation on the shock performance of Zr. • Shock response of pristine and hydride precipitated Zr configurations was investigated using MD simulations. • Hydride precipitation leads to pressure drop, reduced shock velocity, and void formation at the Zr–hydride interface. • At higher piston velocity, spallation occurred in hydride precipitated Zr, whilepristine Zr showed no spallation. • The effects of hydride became more pronounced with increasing precipitate size and hydrogen content in the hydride phases.